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