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