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