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