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