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