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)(11,18,21,15)(12,22,17,13)(19,24,23,20)(25,26,30,33)(27,29,34,31)(28,32,38,40)(35,37,36,39)(1,3,5,8)(2,6,7,4)(9,11,14,21)(10,15,16,18)(12,19,17,23)(13,24,22,20)(27,34)(29,31)(35,36)(37,39)(1,2)(3,4)(5,7)(6,8)(10,16)(12,17)(15,18)(19,23)(25,27)(26,31)(28,36)(29,33)(30,34)(32,37)(35,38)(39,40) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,12,14,17)(10,13,16,22)(11,19,21,23)(15,24,18,20)(25,28)(26,32)(27,35)(29,37)(30,38)(31,39)(33,40)(34,36)(1,3)(2,4)(5,8)(6,7)(9,11)(10,15)(12,23)(13,20)(14,21)(16,18)(17,19)(22,24)(25,27)(26,31)(28,36)(29,33)(30,34)(32,37)(35,38)(39,40) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,13)(10,17)(11,20)(12,16)(14,22)(15,19)(18,23)(21,24)(25,29,30,31)(26,27,33,34)(28,37,38,39)(32,35,40,36)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.