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