One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,19)(12,21)(13,17)(14,20)(15,18)(16,22)(23,24)(25,26,29,33)(27,35,28,31)(30,39,38,34)(32,36,40,37)(2,5)(6,8)(9,11)(10,12)(13,21)(14,16)(15,24)(17,19)(18,22)(20,23)(25,27)(26,31)(28,29)(30,37)(32,34)(33,35)(36,38)(39,40) involution — undirected(1,3)(2,6)(4,7)(5,8)(9,12,13,19)(10,16,17,24)(11,20,21,18)(14,23,15,22)(25,28,29,27)(26,32,33,40)(30,36,38,37)(31,34,35,39)(3,7)(6,8)(11,21)(12,19)(16,24)(22,23)(27,28)(31,35)(32,40)(36,37) 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.