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