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