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