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