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