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