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