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