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