Summary: The best way to see the water is to try and look for the reflection of a light source (sun or light bulb) at a large angle of incidence.
More Details: You see the water on your floor because it reflects light differently than the dry surface of the floor. Namely, the water forms a smooth enough surface that the light reflected off of it can be imaged by your eye. So, when you 'see' the water, you are seeing a specular reflection from some light source as compared to the diffuse reflection from the dry floor.
In addition, the reflectivity of the water increases with increasing angle of incidence which is captured in the figure below. If you stand directly above the water and the light bulb that you are trying to see is directly over your head (with a small offset), then the reflectivity of the water is very low at $\sim2\ \%$, and you may not notice the water. If you try to use a light at the side of the room so that the angle of incidence is large, then the water's reflectivity goes up significantly, and it is much easier to see.
Public domain image taken from http://en.wikipedia.org/wiki/File:Water_reflectivity.jpg