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