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