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