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