One important feature of MOSFET transistors is that they contain an intrinsic (unavoidable, built-in) diode between their drain and source. This diode acts as a catch diode in an H-bridge configuration, and most MOSFET datasheets specify the parameters of this diode. It is thus possible to use this built-in diode of the transistors and not provide external ones if the specification of this diode meet the design requirements. For bipolar transistors there’s no such intrinsic diode so external diodes always have to be provided.
For more explanation, check up this explanation
Note: Use the schematic on your own risk.