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