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