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