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)(11,19)(12,21)(13,15)(14,17)(16,18)(20,23)(22,24)(25,26,30,34)(27,31,36,39)(28,32,35,38)(29,33,37,40)(2,6)(3,7)(9,11,16,15)(10,13,18,19)(12,22,14,20)(17,24,21,23)(25,26)(27,31)(28,32)(29,33)(30,34)(35,38)(36,39)(37,40)(1,3,5,7)(2,4,6,8)(9,12,16,14)(10,17,18,21)(11,20,15,22)(13,23,19,24)(25,27,30,36)(26,31,34,39)(28,29,35,37)(32,33,38,40)(1,4)(2,7)(3,6)(5,8)(9,13)(10,11)(12,23)(14,24)(15,18)(16,19)(17,20)(21,22)(25,26)(27,31)(28,32)(29,33)(30,34)(35,38)(36,39)(37,40) involution — undirected(9,14,16,12)(10,17,18,21)(11,20,15,22)(13,24,19,23)(25,28)(26,32)(27,29)(30,35)(31,33)(34,38)(36,37)(39,40)(9,15,16,11)(10,13,18,19)(12,22,14,20)(17,23,21,24)(25,29)(26,33)(27,35)(28,36)(30,37)(31,38)(32,39)(34,40)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.