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