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