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