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