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