Does the Dra'Azon have a physical presence?

Very little description of the Dra'Azon is given in the book. The clearest statement is given when Fal is being briefed:

the Dra'Azon had made Schar's World one of their Planets of the Dead.  If you were a pure-energy superspecies long retired from the normal, matter-based life of the galaxy, and your conceit was to cordon off and preserve the odd planet or two you thought might serve as a fitting monument to death and futility, Schar's World with its short and sordid history sounded like the sort of place you'd put pretty near the top of your list.

So it appears they were beings of pure energy. I don't think it is clear from Consider Phlebas whether they had Sublimed or not, although being "retired from the normal, matter-based life of the galaxy" would tend to imply it. The Culture wiki states "they were a particularly reclusive, partially Sublimed, Elder civilization", a description that comes from Banks' later novel Matter. They were still clearly able to interact physically with the universe though. For example, all the debris from the fighting on Schar's World was found compressed in a tight ball, under the ice at one of the planet's poles. Clearly only the Dra'Azon were able to have done this.