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