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