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