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