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