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