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