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