# Transform $z$-score to absolute value for visualization

I'm playing with within-module z-score (page 68) which is defined as $$z_i = \frac{k_i - \overline{k}}{SD(k)}$$ where $k_i$ is degree of node $i$ within network module (community). I would like to visualize my network, where diameter of the node will correspond to calculated $z$-score. However, i have no idea how to present negative values on the figure. The first idea that crosses my mind is to compute percentile rank and use it as node's attribute.

Any other ideas?

$size = e^{z_i}$
$size = z_i \;\;\;\;\;\;\;for\; z_i\geq 0$
$size = \frac{1}{-z_i} \;\;\;\;for \;z_i<0$