I don't think you can do this with Log4J properties. I enabled TRACE for like following,
log4j.logger.org.apache.axis2.builder=TRACE log4j.logger.org.apache.axis2.transport.http.ApplicationXMLFormatter=TRACE log4j.logger.org.apache.axis2.transport.http.SOAPMessageFormatter=TRACE
Still you can't get the SOAP messages going in and out. If you're playing around with ESB then of course you can use the Log mediator in inSequence and outSequence to get the SOAP request/response
Easiest way would be to use a tool like TCPMon (shipped with all the WSO2 products and can be found in the bin folder) or SOAP UI.