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)(27,35,38,40)(28,34,30,33)(32,37,39,36)(9,11)(10,14)(12,18)(13,17)(15,21)(16,20)(19,23)(22,24)(25,27,31,38)(26,32,29,39)(28,36,30,37)(33,35,34,40)(2,5)(6,8)(11,17)(12,19)(14,20)(15,22)(25,28,31,30)(26,33,29,34)(27,36,38,37)(32,35,39,40)(9,12,13,19)(10,15,16,22)(11,18,17,23)(14,21,20,24)(25,29,31,26)(27,32,38,39)(28,34,30,33)(35,37,40,36)(1,3,4,7)(2,6,5,8)(11,17)(14,20)(18,23)(21,24)(25,28,31,30)(26,34,29,33)(27,37,38,36)(32,35,39,40)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.