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