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