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