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