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)(11,13)(12,14)(15,16)(18,21)(22,24)(25,26,30,31)(27,32,34,39)(28,29,38,33)(35,40,37,36)(2,3)(4,8)(9,10,12,14)(11,13,15,16)(19,23)(22,24)(26,31)(27,34)(29,33)(35,37)(2,3)(6,7)(9,11,12,15)(10,13,14,16)(17,18,20,21)(19,22,23,24)(25,27)(26,32)(28,37)(29,36)(30,34)(31,39)(33,40)(35,38)(1,3,5,2)(4,7,8,6)(9,11)(10,13)(12,15)(14,16)(17,19,20,23)(18,22,21,24)(25,28)(26,33)(27,35)(29,31)(30,38)(32,36)(34,37)(39,40)(1,4)(2,6)(3,7)(5,8)(9,10)(11,13)(12,14)(15,16)(25,29,30,33)(26,28,31,38)(27,36,34,40)(32,37,39,35)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.