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