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