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