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