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