Every person, agent, or officer thereof engaged in the businesses specified in Section 270, 270.5, 270.6, or 271, shall keep conspicuously posted upon the premises where persons are employed, a notice specifying the name and address of the bank or trust company where the required cash or readily salable securities are on deposit, or the name of the surety or sureties on the bond deposited pursuant to Section 270.5 or 270.6. Failure to keep the notice conspicuously posted is prima facie evidence of a violation of Section 270, 270.5, 270.6, or 271.