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