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