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