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