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