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