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