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