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