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