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