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