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