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