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