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