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