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