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