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