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