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