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