Added the 9_slice image to the settings view. Also added so that the icon looks clicked when clicked.

com.unity.shadergraph/Editor/Drawing/Views/NodeSettingsView.cs

 
         public NodeSettingsView()
         {
+            pickingMode = PickingMode.Ignore;
             AddStyleSheetPath("Styles/NodeSettings");
             var uxml = Resources.Load<VisualTreeAsset>("UXML/NodeSettings");
             uxml.CloneTree(this, null);

com.unity.shadergraph/Editor/Resources/Styles/MaterialNodeView.uss

 }
 
 MaterialNodeView  > #node-border > #title > #button-container > #settings-button.clicked{
-	/*background-color: #2B2B2B;*/
+    background-color: #2B2B2B;
+    background-image : resource("Icons/SettingsIcons_hover");
+    width : 12;
+	height : 12;
 }
 
 MaterialNodeView  > #node-border > #title > #button-container > #settings-button > #icon{

com.unity.shadergraph/Editor/Resources/Styles/NodeSettings.uss

 NodeSettingsView {
+	width: 232;
-	position-left: 215;
-	position-top: 4;
+	position-left: 116;
+	position-top: 15;
+	
+	slice-top: 40;
+	slice-left: 80;
+	slice-right: 25;
+	slice-bottom: 25;
+	padding-top: 30;
+	padding-left: 12;
+	padding-right: 12;
+	padding-bottom: 12;
+	background-image: resource("Icons/Settings_Flyout_9slice");
-	width: 200;
-	
-	background-color: rgba(0, 0, 0, 0.7);
-	border-color: #000000;
-	border-style: solid;
-	border-top-width: 1px;
-	border-bottom-width: 1px;
-	border-right-width: 1px;
-	border-left-width: 1px;
-	border-top-left-radius: 4px;
-	border-top-right-radius: 4px;
-	border-bottom-right-radius: 4px;
-	border-bottom-left-radius: 4px;
+	padding-top: 4;
+	padding-left: 4;
+	padding-right: 4;
+	padding-bottom: 4;
 }
 
 NodeSettingsView > #mainContainer > #title {

com.unity.shadergraph/Editor/Resources/Styles/PBRSettings.uss

 	padding-left: 4;
 	padding-right: 4;
 	padding-bottom: 4;
-	background-color: rgba(0, 0, 0, 0.7);
 }
 
 PBRSettingsView > #container > .row {

com.unity.shadergraph/Editor/Resources/Styles/UnlitSettings.uss

 	padding-left: 4;
 	padding-right: 4;
 	padding-bottom: 4;
-	background-color: rgba(0, 0, 0, 0.7);
 }
 
 UnlitSettingsView > #container > .row {

com.unity.shadergraph/Editor/Resources/Icons/Settings_Flyout_9slice.png.meta

+fileFormatVersion: 2
+guid: 57517c89a809f44458493cef0310e46f
+TextureImporter:
+  fileIDToRecycleName: {}
+  externalObjects: {}
+  serializedVersion: 5
+  mipmaps:
+    mipMapMode: 0
+    enableMipMap: 0
+    sRGBTexture: 1
+    linearTexture: 0
+    fadeOut: 0
+    borderMipMap: 0
+    mipMapsPreserveCoverage: 0
+    alphaTestReferenceValue: 0.5
+    mipMapFadeDistanceStart: 1
+    mipMapFadeDistanceEnd: 3
+  bumpmap:
+    convertToNormalMap: 0
+    externalNormalMap: 0
+    heightScale: 0.25
+    normalMapFilter: 0
+  isReadable: 0
+  grayScaleToAlpha: 0
+  generateCubemap: 6
+  cubemapConvolution: 0
+  seamlessCubemap: 0
+  textureFormat: 1
+  maxTextureSize: 2048
+  textureSettings:
+    serializedVersion: 2
+    filterMode: -1
+    aniso: 1
+    mipBias: -1
+    wrapU: 1
+    wrapV: 1
+    wrapW: -1
+  nPOTScale: 0
+  lightmap: 0
+  compressionQuality: 50
+  spriteMode: 1
+  spriteExtrude: 1
+  spriteMeshType: 1
+  alignment: 0
+  spritePivot: {x: 0.5, y: 0.5}
+  spriteBorder: {x: 0, y: 0, z: 0, w: 0}
+  spritePixelsToUnits: 100
+  alphaUsage: 1
+  alphaIsTransparency: 1
+  spriteTessellationDetail: -1
+  textureType: 2
+  textureShape: 1
+  singleChannelComponent: 0
+  maxTextureSizeSet: 0
+  compressionQualitySet: 0
+  textureFormatSet: 0
+  platformSettings:
+  - serializedVersion: 2
+    buildTarget: DefaultTexturePlatform
+    maxTextureSize: 2048
+    resizeAlgorithm: 0
+    textureFormat: -1
+    textureCompression: 1
+    compressionQuality: 50
+    crunchedCompression: 0
+    allowsAlphaSplitting: 0
+    overridden: 0
+    androidETC2FallbackOverride: 0
+  - serializedVersion: 2
+    buildTarget: Standalone
+    maxTextureSize: 2048
+    resizeAlgorithm: 0
+    textureFormat: -1
+    textureCompression: 1
+    compressionQuality: 50
+    crunchedCompression: 0
+    allowsAlphaSplitting: 0
+    overridden: 0
+    androidETC2FallbackOverride: 0
+  - serializedVersion: 2
+    buildTarget: iPhone
+    maxTextureSize: 2048
+    resizeAlgorithm: 0
+    textureFormat: -1
+    textureCompression: 1
+    compressionQuality: 50
+    crunchedCompression: 0
+    allowsAlphaSplitting: 0
+    overridden: 0
+    androidETC2FallbackOverride: 0
+  spriteSheet:
+    serializedVersion: 2
+    sprites: []
+    outline: []
+    physicsShape: []
+    bones: []
+    spriteID: 
+    vertices: []
+    indices: 
+    edges: []
+    weights: []
+  spritePackingTag: 
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

com.unity.shadergraph/Editor/Resources/Icons/Settings_Flyout_9slice@2x.png.meta

+fileFormatVersion: 2
+guid: a6abafca3e442ca4d970a1f8a2c70b0a
+TextureImporter:
+  fileIDToRecycleName: {}
+  externalObjects: {}
+  serializedVersion: 5
+  mipmaps:
+    mipMapMode: 0
+    enableMipMap: 1
+    sRGBTexture: 1
+    linearTexture: 0
+    fadeOut: 0
+    borderMipMap: 0
+    mipMapsPreserveCoverage: 0
+    alphaTestReferenceValue: 0.5
+    mipMapFadeDistanceStart: 1
+    mipMapFadeDistanceEnd: 3
+  bumpmap:
+    convertToNormalMap: 0
+    externalNormalMap: 0
+    heightScale: 0.25
+    normalMapFilter: 0
+  isReadable: 0
+  grayScaleToAlpha: 0
+  generateCubemap: 6
+  cubemapConvolution: 0
+  seamlessCubemap: 0
+  textureFormat: 1
+  maxTextureSize: 2048
+  textureSettings:
+    serializedVersion: 2
+    filterMode: -1
+    aniso: -1
+    mipBias: -1
+    wrapU: -1
+    wrapV: -1
+    wrapW: -1
+  nPOTScale: 1
+  lightmap: 0
+  compressionQuality: 50
+  spriteMode: 0
+  spriteExtrude: 1
+  spriteMeshType: 1
+  alignment: 0
+  spritePivot: {x: 0.5, y: 0.5}
+  spriteBorder: {x: 0, y: 0, z: 0, w: 0}
+  spritePixelsToUnits: 100
+  alphaUsage: 1
+  alphaIsTransparency: 0
+  spriteTessellationDetail: -1
+  textureType: 0
+  textureShape: 1
+  singleChannelComponent: 0
+  maxTextureSizeSet: 0
+  compressionQualitySet: 0
+  textureFormatSet: 0
+  platformSettings:
+  - serializedVersion: 2
+    buildTarget: DefaultTexturePlatform
+    maxTextureSize: 2048
+    resizeAlgorithm: 0
+    textureFormat: -1
+    textureCompression: 1
+    compressionQuality: 50
+    crunchedCompression: 0
+    allowsAlphaSplitting: 0
+    overridden: 0
+    androidETC2FallbackOverride: 0
+  spriteSheet:
+    serializedVersion: 2
+    sprites: []
+    outline: []
+    physicsShape: []
+    bones: []
+    spriteID: 
+    vertices: []
+    indices: 
+    edges: []
+    weights: []
+  spritePackingTag: 
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: