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)(13,16)(14,17)(15,18)(19,20)(23,29)(24,31)(26,33)(28,35)(30,32)(34,36) involution — undirected(1,2,3,4)(5,7)(6,10)(8,14)(9,13)(11,16)(12,17)(15,19)(18,20)(21,22,25,27)(23,26,30,34)(24,28,31,35)(29,33,32,36)(7,13)(10,16)(14,19)(17,20)(21,23,25,30)(22,26,27,34)(24,32,31,29)(28,36,35,33)(6,11)(10,16)(12,18)(17,20)(22,27)(26,34)(28,35)(33,36) involution — undirected(5,8,9,15)(6,12,11,18)(7,14,13,19)(10,17,16,20)(22,27)(26,34)(28,35)(33,36)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.