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