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