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