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)(23,25)(24,31)(26,30)(27,34)(28,32)(29,35)(33,36) involution — undirected(1,2)(3,4)(5,7,9,15)(6,10,11,13)(8,16,17,14)(12,20,19,18)(21,23,25,22)(24,27,33,29)(26,30,32,28)(31,35,36,34)(2,4)(21,24,32,35,25,33,26,34)(22,27,30,36,23,29,28,31)(6,11)(10,13)(12,19)(18,20)(22,23)(27,29)(28,30)(31,36) involution — undirected(2,4)(5,8,9,17)(6,12,11,19)(7,14,15,16)(10,18,13,20)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.