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