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