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