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