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