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