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