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