俗话说得好的英文

Well goes an old saying, "…"
= As an old saying goes(runs, says), "…"
= An old saying goes, "…"
= It's an old saying (that)子句
例∶俗话说得好：「诚实为上策」。
As an old saying goes, "Honesty is the best policy."

as/like the old saying goes, 后面直接加上原句，原句用斜体表示比较正规
或者it is an old saying goes that 加上从句

As the saying goes