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