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