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