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