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