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