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