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