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