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