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