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