digraph G {
  bgcolor="white";
  rankdir="LR";
  nodesep=0.5;
  fontsize=11;

  node [shape="ellipse", style="filled"];

  {
    node [fillcolor="cyan"];
    b1_0 [label="base-0"];
    b1_1 [label="patch-1"];
    b1_2 [label="patch-2"];
    b1_3 [label="patch-3"];
    b1_4 [label="patch-4"];
    b1_5 [label="patch-5"];
    b1_6 [label="patch-6"];
  }
  {
    node [fillcolor="magenta"];
    b2_1 [label="patch-1"];
    b2_2 [label="patch-2"];
    b2_3 [label="patch-3"];
    b2_4 [label="patch-4"];
    b2_5 [label="patch-5"];
  }
  {
    node [fillcolor="yellow"];
    b3_1 [label="patch-1"];
    b3_2 [label="patch-2"];
    b3_3 [label="patch-3"];
    b3_4 [label="patch-4"];
    b3_5 [label="patch-5"];
  }

  b1_0 -> b1_1 -> b1_2 -> b1_3 -> b1_4 -> b1_5 -> b1_6;
  b1_1 -> b2_1 -> b2_2 -> b2_3 -> b2_4 -> b2_5;
  b1_1 -> b3_1 -> b3_2 -> b3_3 -> b3_4 -> b3_5;

  b3_3 -> b1_5;
  b3_2 -> b2_3;
  b2_4 -> b1_6;
}