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