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