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