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