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