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