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