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