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