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