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