Depending on the hard drive, there may well be a model with 32MB of cache that has a faster transfer rate than another model with 64MB of cache. But that really has nothing to do with the cache - the real reason would be how densely the data is stored on the platters and/or the rotational speed of the drive.
Even if you could change the cache size of the drive you have (which as Hawkeye says really isn't possible), it wouldn't change the basic drive geometry and spin rate, so it wouldn't change how fast the drive can transfer data.