One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,12)(8,17)(9,19)(10,14)(11,16)(13,18)(15,20)(21,22)(23,29)(24,35)(25,30)(26,32)(27,31)(28,33)(34,36) involution — undirected(5,7,9,16,10,15,18,8)(6,11,13,12,14,17,19,20)(21,23,25,33)(22,28,30,29)(24,27,34,26)(31,35,32,36)(1,2,3,4)(7,15)(8,16)(11,17)(12,20)(21,24,27,33,25,34,26,23)(22,29,32,36,30,28,31,35)(5,8,18,15,10,16,9,7)(6,12,19,11,14,20,13,17)(22,30)(28,29)(31,32)(35,36)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.