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