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