In standalone.xml, add the following system property,

<property name="org.apache.cxf.logging.enabled" value="true"/>

Also add the following valve settings in 'urn:jboss:domain:web:1.4'

 <subsystem xmlns="urn:jboss:domain:web:1.4" default-virtual-server="default-host" native="false">
    ...
    ...
   <valve name="RequestLogging" module="org.jboss.as.web" class-name="org.apache.catalina.valves.RequestDumperValve"/>
</subsystem>