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