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