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