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