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