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