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