digraph G {
   node [shape=circle];
   a -> b [label="label",lblstyle="draw=red,cross out"];
   b -> c [label="test",lblstyle="below=0.5cm,rotate=20,fill=blue!20"];
   a [label="aa",lblstyle="blue"];
   b [lblstyle="font=\Huge"];
   c [label="ccc", lblstyle="red,rotate=90"];
   rankdir=LR;
   label="Graph label";
   lblstyle="draw,fill=red!20";
}