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