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