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