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