Unlike other touch attacks, this one specifically says that the range is personal and target is you (other touch spells indicate the target(s) as creature touched and range as "touch"). Am I reading it right, that this spell is a personal buff that enhances your touch/melee unarmed/claw attacks?
Also, identical spell effects overlap, but if this spell is a buff, then each casting would be a different spell effect if you cast it with a different element. So if it IS a buff, could you cast it four times, so that your touch does 1d6 points of damage with each element, and your target has to make 4 saves (one for each extra effect)?