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