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