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