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