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