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