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)(11,14)(12,15)(13,17)(16,20)(18,22)(19,21)(23,24)(25,26,30,28)(27,31,34,36)(29,37,39,32)(33,35,40,38)(2,5)(6,8)(9,11,13,18)(10,14,17,22)(12,19,20,24)(15,21,16,23)(25,27)(26,31)(28,36)(29,38)(30,34)(32,40)(33,37)(35,39)(1,3)(2,6)(4,7)(5,8)(10,15)(12,20)(14,21)(16,17)(19,24)(22,23)(25,28,30,26)(27,33,34,40)(29,32,39,37)(31,38,36,35)(3,7)(6,8)(11,18)(14,22)(19,24)(21,23)(27,34)(31,36)(33,40)(35,38) 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.