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