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