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