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