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