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