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