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