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