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