The best way to root sansevieria in water is possibly to use a rooting hormone? This will help the plant to develop strong roots. To do this, take a cutting from the plant and remove the bottom leaves. Dip the cut end of the plant into the rooting hormone.
Place the cutting into a glass of water or jar of water, making sure that the leaves are above the waterline. Place the glass in a bright location but out of direct sunlight, and wait for the roots to develop.
This can take anywhere from a few days to a few weeks, not sure about this particular plant. Once the roots are a few inches long, you should be alright to transplant the cutting into a pot filled with well-drained potting mix.
Hope that helps.