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