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