GT

TShirt[c_] := Graphics[{c, t}];
TShirt[{c1_, c2_}] :=
  Graphics[{EdgeForm[Black], c1, t, c2,
    Table[Line[{{-w, 0.4 + i/10}, {w, 0.4 + i/10}}], {i, 10}]}];
PPink = RGBColor[0.850, 0.380, 0.905];
Lilac = RGBColor[0.690, 0.509, 0.890];
(* 2 lectures missing *)
data = {
   Purple, Black, LightBlue, Black, Gray, Darker[Blue, 0.7],
   Blue, {White, Blue}, Lilac, Darker[Blue, 0.7], Black,
   Darker[Blue, 0.7], LightBlue, PPink, Black, Gray, PPink,
   Blue, {Blue, White}, Black, PPink, Lilac
   };
w = 0.4;
t = Polygon[{{-w, 0.4}, {-w, 1.4}, {-w - 0.2, 1}, {-w - 0.3,
     1.2}, {-w - 0.1, 1.7}, {-w + 0.2, 1.7}, {0, 1.6},
    {w - 0.2, 1.7`}, {w + 0.1, 1.7`}, {w + 0.3, 1.2`}, {w + 0.2,
     1}, {w, 1.4`}, {w, 0.4`}
    }];
graph = Table[
  data[[i]] -> data[[i + 1]], {i, Length[data] - 1}]; GraphPlot[graph,
  DirectedEdges -> True,
 VertexRenderingFunction -> (Inset[TShirt[#2], #1, {0, 1}, 0.4] &),
 PlotStyle -> Black, ImageSize -> {500}, Method -> "SpringEmbedding"]