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