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