Are you testing this at no load? It looks like the controller is switching for a cycle (the large peak you see) and then skips a few cycles while the diode and switch capacitance rings with the output inductor. You are mostly seeing components at a higher frequency than the switching frequency in that scope shot. The datsheet value was probably taken with the system operating under load, which would put the converter in CCM mode, which would avoid the ringdown period.
At these high frequencies the voltage across the electrolytic capacitor is going to be driven by the ESR and ESL more than the bulk capacitance value, which can be different between capacitors with the same capacitance and voltage rating. A ceramic capacitor in addition the electrolytic might lead to an improvement as it has very low ESR and ESL.
A small R-C snubber on the switching node would also reduce some of the high frequency ringing.
Some of this ripple may also be due to to your measurement technique. Measuring the ripple voltage is very sensitive to the probe and ground lead location, which can lead to ripple voltage measurements that are larger than the actual value. A long ground lead can resonate with the scope input capacitance, increasing the measured voltage. The ground lead loop can also couple to magnetic fields on the board, which can induce signals that don't actually exist on what what you are measuring. There is a lot of guidance about this online. Dave did a video on it at some point:
I don't think its contributing to the ripple you are seeing, but I would agree that you need more input capacitance on the PCB. The reference schematic assumes the IC is on a PCB with enough capacitance for decoupling, which is not the case for for your PCB with the long wires connecting to a power supply. The ripple current on the input of a buck converter is worse than the output so input capacitance is pretty important. An electrolytic capacitor similar to what you are using for the output filtering would work in addition to the existing ceramic capacitor. Without this capacitor you may start seeing some stability issues at higher current.