Each member of the board shall be entitled to receive a per diem at the rate of 80 percent of the rate established by Section 34-24-54 for each day or any portion thereof that the member of the board is in attendance at a meeting of the board or any function of the board, plus an amount not to exceed the per diem expense and transportation costs allowed to Alabama state employees for in-state travel for each day actively engaged in the duties of their office. All expenditures by the board shall be made only on requisition signed by the president or the executive director of the board.