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