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