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