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