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