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