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