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