testgraph.gv

digraph test {
      subgraph cluster_open {
    open
    label=open
    color=green
    open -> waiting [label=start]
    open -> assigned [label=assign]
    open -> open [label=alert]
    waiting [shape=box color=black];
    waiting -> waking [label=wake]
        subgraph cluster_waking {
    waking
    label=waking
    color=black
      phoning [shape=box color=green];
      phoning -> phoning [label=retry]
      phoning -> cancelled [label=fail]
      phoning -> answered [label=answer]
      waiting [shape=box color=black];
      waiting -> phoning [label=phone]
      failed [shape=box color=black];
      failed -> cancelled [label=cancel]
      failed -> phoning [label=retry]
      cancelled [shape=box color=black];
      answered [shape=box color=black];
    }
  }
  assigned [shape=box color=black];
  assigned -> assigned [label=alert]
  assigned -> closed [label=close]
  closed [shape=box color=black];
}