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