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)(26,32)(28,35)(33,39)(36,38) involution — undirected(2,6)(3,7)(12,19)(16,22)(18,23)(20,24)(25,26)(27,33)(28,34)(29,39)(30,35)(31,32)(36,40)(37,38) involution — undirected(1,2,5,6)(3,4,7,8)(10,15)(11,17)(16,22)(18,23)(25,27,31,29)(26,33,32,39)(28,36,35,38)(30,37,34,40)(9,11,14,17)(10,13,15,21)(12,18,19,23)(16,20,22,24)(25,28,31,35)(26,34,32,30)(27,36,29,38)(33,40,39,37)(1,3)(2,4)(5,7)(6,8)(9,12)(10,16)(11,18)(13,20)(14,19)(15,22)(17,23)(21,24)(25,29,31,27)(26,33,32,39)(28,38,35,36)(30,37,34,40)(1,4)(2,7)(3,6)(5,8)(9,13)(10,17)(11,15)(12,20)(14,21)(16,23)(18,22)(19,24)(25,30,31,34)(26,35,32,28)(27,37,29,40)(33,38,39,36)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.