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