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