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