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"]