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