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