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