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