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