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