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