Graphviz and Finite Automata diagrams - III

Now, to bring down the state q3, I have used subgraph cluster, which works. If you try the same subgraph cluster technique for your graph, you may need to try to tweak few times.

digraph finite_state_machine {
    rankdir=LR;
    ranksep=0.5;
    
    node [shape = point, color=white, fontcolor=white]; start;
    node [shape = doublecircle, color=black, fontcolor=black]; q3;
    node [shape = circle]; q1;
   
    subgraph cluster0 {
    start -> q1;
      q1 -> q2 [ label = "a" ];
      q2 -> q1 [ label = "a" ];
      q1 -> q3 [ label = "b" ];
      q2 -> q2 [ label = "b" ];
    }
    subgraph cluster1 {
      q3;
    }
    q3 -> q2 [ label = "a" ];
    q3 -> q1 [ label = "b" ];
 
}