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