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