The input cap is C1 - stock value is 0.01uf (10nf), I’d crank it up to 0.1 (100nf); this is the component that determines how much low end goes into the circuit.
Edit: because you’ve got a high value resistor before the cap (2M2 going to ground) forming half of the high pass filter (hpf) your ‘corner frequency’ is about 7Hz, try it as it is before changing it out.
C2 is the 0.047uf that goes into the 4k7 resistor, then to the gain control. That might be ok as it is, but if you find that you’re losing too much low end, or that your distortion is a bit ‘fuzzy’ then increase the value of this cap, you can work up and experiment (I think the next value would be something like 0.068, then 0.1)
C3 is a tiny cap, and shaves off all of the extreme, unpleasant noise that we don’t want amplified. You can leave that as is.
The coupling cap is the 4.7uf polarised electrolytic after the opamp stage. That filters the audio signal so that we don’t have DC noise in the audio path. In guitar and bass pedals anything of that size (or bigger) is generally used for DC filtering -C6 and C7 are large values (relatively speaking) and do just that to the power supply input at ‘+9v (T)’.
Your output cap is C5 and in this configuration is acting as half of a low pass filter (along with the10k resistor) so should be fine as is.
then you’ve got a final clipping stage (the 3 diodes going to ground) before the master volume control.
Depending on what you want to use it for then you can decrease the value of the gain pot; 500k is a LOT of filth!
Hope this helps.