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