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