One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(4,6)(7,8,13,18)(9,19,20,30)(10,24,26,32)(11,17,12,16)(14,23,28,22)(15,27,31,25)(21,35,34,29)(33,37,38,36)(7,9,11,22,13,20,12,23)(8,14,16,19,18,28,17,30)(10,21,25,36,26,34,27,37)(15,29,24,33,31,35,32,38)(3,4,5,6)(9,20)(14,28)(19,30)(21,34)(22,23)(29,35)(33,38)(36,37)(7,10)(8,15)(9,21)(11,25)(12,27)(13,26)(14,29)(16,24)(17,32)(18,31)(19,33)(20,34)(22,36)(23,37)(28,35)(30,38) involution — undirectedA 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.