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