I found the Super Mario Bros chess set to be very accessible. All the pieces are very distinct, they’re brightly colored, the board itself is high contrast, and everything is somewhat bigger than average chess pieces.

Have you seen those small travelling chess sets with holes in the squares and pins under the pieces. I've played against a blind opponent who used a slight larger version of one of those with the black squares slightly raised above the white. The full size board is played by the sighted player who also moves the opponents pieces when they declare their move. The VI player can examine their board of pieces with their hands, the pieces staying in the played positions by virtue of pins and sockets.

http://www.braillechess.org.uk/equipment/chesssets.html