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