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