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