The Director may suspend a license pursuant to Section 7 and require the licensee to cease doing business. The Director shall issue a written order of suspension setting forth the reasons for the suspension and for requiring the registrant to cease the purchasing or brokering of slaughter livestock until a hearing has been held. Such written order shall be served personally on the respondent, or by registered or certified mail sent to the respondent’s business address as shown in his latest notification to the Department.