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