You won't find such a relationship but you can find tables with "usual" sets of value.
One of them ( from an engineering school class ) will give you usual Cv values for the following void ratios :
e= 0.8 Cv = 10-3 cm2/s
e= 1.08 Cv = 8 10-4 cm2/s
e= 1.45 Cv = 6 10-4 cm2/s
e= 2.00 Cv = 3 10-4 cm2/s
e= 2.86 Cv = 10-4 cm2/s
But be careful, this is just for preliminary design, it will never replace lab tests !