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