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