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