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