Physics and physics education in the United States suffer from severe (and, in some cases, worsening) underrepresentation of Black, Latinx, and Native American people of all genders and women of all races and ethnicities. In this paper, we describe an approach to facilitating physics students' collective and continued education about such underrepresentation; its connections to racism, sexism, and other dimensions of marginalization; and models of allyship that may bring about social change within physics. Specifically, we focus on the efforts of undergraduate students, graduate students, and postdocs who are members of a student-run diversity-oriented organization in the physics department at the University of Colorado Boulder (CU), a large, selective, predominantly White public university with high research activity. This group's education was accomplished through quarterly Diversity Workshops. Here we report on six Diversity Workshops that were co-designed and facilitated by the authors. We describe the context, motivation, and goals of the workshops, the theories underlying their design and implementation, and their content. In addition, we discuss workshop attendance and suggest strategies for maintaining high attendance in the future. Because the details of our workshops were tailored to the specific needs and interests of a particular student organization, our workshop agendas may not be widely applicable beyond our local context. Nevertheless, our model, design principles, and facilitation strategies may be transferable to other contexts and provide inspiration to other diversity-oriented student groups.