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