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