Have you seen this National Instruments Tutorial? It details some getting started steps with WSN devices and explains how to configure the network.
Also, how does Graph Theory relate to you application? Any details about this would be very helpful.
Would you be able to explain your application in more depth along with the specific information that you are looking to obtain in relation to Graph Theory? We do not have any documentation that is related to graph theory and our Wireless Sensor Networks, but with a better understanding of your objective I will be able to better assist with this.
If you are hoping to learn more about how our WSN nodes communicate then this link will be very helpful, as it explains how the WSN system is built on a mesh network. This other forum post also reinforces that the signal routing is abstracted from the user and that it is built on the ZigBee protocol.