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