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