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