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