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