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