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