The commission shall appoint a director of corrections who shall be qualified by training and experience in penology. He shall hold office at the pleasure of the commission except that he may be removed for cause and only after a public hearing before the commission. He shall receive such salary as shall be appropriated by the legislature, together with actual and necessary traveling and other expenses. The director shall be the chief administrative officer of the commission and shall be responsible to the commission for the exercise of the powers and duties prescribed and conferred by this act, and for such other powers and duties as may be assigned by the commission, subject at all times to its control. Subject to the provisions of this act, and to the rules and regulations adopted by the commission, the director shall have full power and authority to supervise and control the affairs of the department, and the several bureaus thereof, and he shall carry out the orders of the commission.