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)(11,17)(12,14)(13,16)(15,19)(18,23)(20,21)(22,24)(25,26,31,35)(27,32,36,38)(28,30,34,40)(29,33,39,37)(1,2,4,6)(3,5,8,7)(9,11)(10,15)(12,17)(13,18)(14,19)(16,22)(20,23)(21,24)(25,27)(26,32)(28,37)(29,30)(31,36)(33,34)(35,38)(39,40)(1,2,4,6)(3,5,8,7)(13,21)(16,20)(18,24)(22,23)(27,36)(29,39)(32,38)(33,37)(1,2,4,6)(3,7,8,5)(9,12,14,10)(11,17,19,15)(13,16,21,20)(18,22,24,23)(25,28)(26,30)(27,37)(29,32)(31,34)(33,36)(35,40)(38,39)(1,2)(3,5)(4,6)(7,8)(9,13)(10,16)(11,18)(12,20)(14,21)(15,22)(17,23)(19,24)(25,29)(26,33)(27,30)(28,38)(31,39)(32,34)(35,37)(36,40) involution — undirected(1,3)(2,5)(4,8)(6,7)(9,11)(10,17)(12,15)(13,18)(14,19)(16,23)(20,22)(21,24)(25,30)(26,34)(27,29)(28,35)(31,40)(32,33)(36,39)(37,38) 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.