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