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