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