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