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