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)(11,17)(12,16)(13,18)(14,15)(19,24)(20,21)(22,23)(25,26)(27,33)(28,37)(29,31)(30,34)(32,35)(36,38)(39,40) involution — undirected(1,3,5,6)(2,4,7,8)(9,11)(10,13)(12,20)(14,18)(15,17)(16,24)(19,22)(21,23)(25,27,32,29)(26,33,35,31)(28,36,30,39)(34,40,37,38)(10,15)(11,18)(16,23)(19,20)(25,28,32,30)(26,34,35,37)(27,36,29,39)(31,38,33,40)(9,11)(10,13)(12,19)(14,18)(15,17)(16,21)(20,22)(23,24)(25,29,32,27)(26,31,35,33)(28,36,30,39)(34,40,37,38)(1,4,5,8)(2,6,7,3)(9,12)(10,16)(11,19)(13,21)(14,22)(15,23)(17,24)(18,20)(25,30,32,28)(26,34,35,37)(27,36,29,39)(31,40,33,38)(1,2)(3,4)(5,7)(6,8)(9,13)(10,11)(12,21)(14,17)(15,18)(16,19)(20,23)(22,24)(25,31)(26,27)(28,38)(29,35)(30,40)(32,33)(34,36)(37,39) 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.