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