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