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