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