Hello,
the GUI is available, you just have to add a few things to the configuration to enable it:
Configuring Web User Interface Access
http://www.cisco.com/c/en/us/td/docs/routers/access/4400/software/configuration/guide/isr4400swcfg/bm_isr_4400_sw_config_guide_chapter_011.html#task_AEE38B2E6B5A4971AFB1C06BA8382695