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