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