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