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