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