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