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