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