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