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