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