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