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