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