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