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