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