One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,9,13)(7,14,15,19)(8,10,17,12)(11,18,20,16)(21,22,25,28)(23,26,30,33)(24,27,31,34)(29,35,36,32)(1,2)(3,4)(6,10)(7,15)(8,17)(11,19)(12,13)(14,20)(21,23)(22,26)(24,29)(25,30)(27,32)(28,33)(31,36)(34,35) involution — undirected(2,4)(21,24,25,31)(22,27,28,34)(23,29,30,36)(26,32,33,35)(5,7,9,15)(6,11,13,20)(8,18,17,16)(10,14,12,19)(21,23)(22,26)(24,29)(25,30)(27,32)(28,33)(31,36)(34,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.