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