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