Run Raster To Point (warning, this can be a lot of points so best to try a small extent [snap raster set to your fdr of course]) from your flow direction raster. Then create a marker style with arrows pointing in the proper direction for each code 0 (use a point for that), 1,2,4,8 .. 128.
There is a way to symbolize fields with multidimensional datasets, if someone has worked out how to apply that symbology to a flow direction raster, I would LOVE to see the instructions here. Steve Lynch can you help, or can you encourage one of your colleagues to post some guidance here (or better yet, a KB article!!).
We old-timers really miss ArcInfo Workstation's GRIDDIRECTION command!