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