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