Place the cursor inside "graph" to get some refactoring options

graph {

# To refactor nodes, place the cursor left to a node name
a -- b
a -- c;
a -- d;

# Hover over color names to get a color picker
b -- b [color=blue]
b -- d [color="#ff0000"];

# Get completion when assigning a shape or color
b [shape=box, color=yellow];

a; # You can remove optional ; by placing the cursor left to a semicolon

}