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