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