Improve highlighing in graph

templates/graph.html

@@ -22,10 +22,17 @@
         var options = {
             edges: {
                 arrows: 'to',
+                color: {
+                    highlight: 'green'
+                }
             },
 
             nodes: {
-                shape: 'box'
+                shape: 'dot',
+                size: 15,
+                font: {
+                    background: 'white'
+                }
             }
         };