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