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