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