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