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