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