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