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)(11,17,18,14)(12,15,20,22)(19,23,24,21)(25,26)(27,34)(28,31)(29,32)(30,36)(33,38)(35,40)(37,39)(2,5)(6,8)(9,11)(10,14)(12,19)(13,18)(15,21)(16,17)(20,24)(22,23)(25,27)(26,30)(28,37)(29,35)(31,34)(32,39)(33,40)(36,38) involution — undirected(11,18)(14,17)(19,24)(21,23)(26,31)(28,38)(30,34)(32,33)(36,37)(39,40) involution — undirected(1,3,4,7)(2,6,5,8)(12,20)(15,22)(19,24)(21,23)(26,32)(30,39)(31,33)(34,40)(9,12,13,20)(10,15,16,22)(11,19,18,24)(14,21,17,23)(27,35)(30,39)(34,40)(36,37)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.