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