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