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