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