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