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