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