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