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