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