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