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