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