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