The stripe end of a diode is the cathode, (bar in diode symbol) and indicates the way that (conventional) current will flow. Taking the bridge as a whole, current from the transformer secondary connected to the AC terminals will flow OUT of the positive terminal (pair of cathodes) and back IN to the negative terminal (pair of anodes).
Its the opposite way round to what you may expect because the bridge is supplying current to the load, not consuming current from a DC supply rail.
If that doesn't satisfy you, draw the bridge schematic using individual diode symbols, labelling the bridge terminals AC1, AC2, DC1, DC2, with a voltage source across the AC terminals and a load resistor across its DC terminals, Let AC1 be positive with respect to AC2, and follow through on the schematic which diodes conduct current, which block, and the direction of the current through the load. Repeat with AC2 positive with respect to AC1.