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