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