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