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