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)(11,19)(12,14)(13,16)(15,18)(17,23)(20,24)(21,22)(25,26,31,35)(27,36,38,32)(28,33,39,29)(30,34,40,37)(1,2)(3,6)(4,7)(5,8)(25,27,31,38)(26,32,35,36)(28,37,39,34)(29,30,33,40)(1,3,5,4)(2,6,8,7)(9,11,15,13)(10,16,18,19)(12,20,23,22)(14,21,17,24)(25,28)(26,33)(27,34)(29,35)(30,32)(31,39)(36,40)(37,38)(1,4,5,3)(2,7,8,6)(9,12)(10,17)(11,20)(13,22)(14,18)(15,23)(16,24)(19,21)(25,29,31,33)(26,28,35,39)(27,30,38,40)(32,37,36,34)(9,13,15,11)(10,16,18,19)(12,22,23,20)(14,21,17,24)(25,28)(26,33)(27,37)(29,35)(30,36)(31,39)(32,40)(34,38)(9,14,15,17)(10,12,18,23)(11,21,13,24)(16,20,19,22)(25,30)(26,34)(27,33)(28,32)(29,38)(31,40)(35,37)(36,39)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.