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)(11,15)(12,16)(13,14)(17,18,21,20)(19,22,24,23)(26,27)(28,35)(29,37)(39,40)(2,4)(6,7)(10,14)(12,15)(17,18)(19,23)(20,21)(22,24)(25,26,30,27)(28,33,35,31)(29,34,37,32)(36,39,38,40)(17,19)(18,22)(20,23)(21,24)(25,27,30,26)(28,33,35,31)(29,34,37,32)(36,40,38,39)(1,3,5,8)(2,6,4,7)(9,11)(10,15)(12,14)(13,16)(17,19)(18,23)(20,22)(21,24)(25,28,30,35)(26,31,27,33)(29,38,37,36)(32,40,34,39)(1,4,5,2)(3,6,8,7)(9,12,13,15)(10,16,14,11)(17,20,21,18)(19,23,24,22)(25,29,30,37)(26,32,27,34)(28,36,35,38)(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.