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