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