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