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