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