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