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