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