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