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