On the bridge, in the lower right corner of the screen there is a round tabletop world map, with the edge rotating slowly. If the dome over it is blue, you should be able to click it to get to the strategy map; if red you need to visit another location on the Raven (indicated by an exclamation mark on the bottom of the screen over the relevant icon).
Mousing over to dome, you should get a tooltip saying 'Strategy Map, Interact', similar to mousing over an NPC, and the dome and sections of the edge that are rotating get highlighted in white.
The first tutorial tip you get in the single player story campaign (after the greeting from Maxos) is how to talk to NPCs and access the strategy map (though it isn't particularly thorough, just saying to click on the "strategy globe").
