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