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