1 digraph {

     2     size="5,4"

     3     1 [label="  start state  ", shape=circle, style=filled, color=blue]

     4     2 [label="start/end state", shape=doublecircle, style=filled, color=blue]

     5     3 [label=" internal state", shape=circle, style=filled, color=red]

     6     4 [label="  end state    ", shape=doublecircle, style=filled, color=green]

     7 }