Launch a flow in a modal dialog from a List Button using Aura Component that renders ListView

Try the below code, this might help you to run flow in a modal dialog.

<aura:component>
     <aura:attribute name="{!isOpen}" type="Boolean" default="false" access="private"/>
     <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
      <aura:if isTrue="{!v.isOpen}">
            <div style="height: 640px;">
                <section role="dialog" tabindex="-1" class="slds-modal slds-fade-in-open">
                    <div class="slds-modal__container">
                        <header class="slds-modal__header slds-modal__header_empty">
                            <lightning:buttonIcon iconName="utility:close" class="slds-modal__close" onclick="{!c.closeFlowModal}"/>
                        </header>
                        <div class="slds-modal__content slds-p-around_medium">
                            <lightning:flow aura:id="flow" onstatuschange="{!c.closeModalOnFinish}" />
                        </div>
                    </div>
                </section>
                <div class="slds-backdrop slds-backdrop_open"></div>
            </div> 
        </aura:if>
</aura:component>

doInit : function(component, event, helper) {
       component.set('v.isOpen', true);
       var flow = component.find('flow');
       flow.startFlow('Flow_Name');
    },
closeFlowModal : function(component, event, helper) {
        component.set("v.isOpen", false);
    },
closeModalOnFinish : function(component, event, helper) {
        if(event.getParam('status') === "FINISHED") {
            component.set("v.isOpen", false);
        }
    }