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