1. A computer-implemented method, comprising: generating, by a processor, a plurality of test scripts, a test script from among the plurality of test scripts generated by performing: initiating a voice call interaction with a speech application, the speech application comprising a network of interaction nodes; and repeatedly performing, until a stopping condition is encountered, the steps of: executing the voice call interaction with the speech application by traversing through one or more interaction nodes from among the network of interaction nodes until an interaction node requiring a response is encountered; selecting an utterance generation mode corresponding to the interaction node; determining a response to be provided corresponding to the interaction node of the speech application based on the utterance generation mode; and providing the response to the speech application, wherein the test script comprises instructions for traversing interaction nodes involved during a course of the voice call interaction, and, instructions for provisioning one or more responses to the speech application during the course of the voice call interaction; identifying, by the processor, one or more test scripts from among the plurality of test scripts based on a pre-determined objective; and providing, by the processor, the one or more test scripts to a user for facilitating testing of the speech application.