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