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