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