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