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