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