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