Congruence Pic

node[a_, p_, b_] := PowerMod[a, b, p];
p = 37;
res = Table[
   GraphPlot[Table[i -> node[i, p, k], {i, 1, p - 1}],
    PlotStyle -> Black, Method -> "CircularEmbedding",
    ImageSize -> 100, PackingMethod -> "ClosestPacking"], {k, 1,
    p - 1}];
res2 = Table[
   res[[If[6 i + j < 37, 6 i + j, 37]]], {i, 0, 5}, {j, 1, 6}];
GraphicsGrid[res2]