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