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