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