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