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